Certain types of electrical circuits require the use of resistors that are able to handle high levels of current and produce a low resistance. Standard types of resistors such as carbon composition or wire wound resistors are limited in their ability to handle high current. One alternate method of providing a high current, low resistance resistor is to place a metal jumper on the printed circuit board in place of a conventional resistor. The metal jumper is typically fabricated from a metal alloy that has a higher resistance than the remaining portions of the circuit and serves to provide a low resistance, high current component. The metal alloy is selected to provide a constant resistance over temperature. These types of resistors are typically made from strips or wires of the metal alloy. The resistors end up looking much like staples and are typically used in printed circuit boards having thru-hole configurations. The resistance of the resistor is changed by varying the thickness of the strip or wire.
While this type of resistor works well in applications having thru-hole circuit boards applications, it is difficult to use with surface mount circuit boards. The small legs of the staple provide minimal area for the solder to form a fillet, and the staples are difficult to package and handle in high-speed auto placement equipment. In addition, this configuration is mechanically unstable unless it is anchored to the printed circuit board. Prior to soldering, it is difficult if not impossible to keep the staple type of wire resistor in proper orientation. Without the aid of a hole or other mechanical stabilizing means, the staple falls over prior to soldering.
It would be desirable if a high current, low resistance, surface mountable resistor could be provided that could be easily packaged and handled by auto placement equipment. In addition, it would be highly desirable if the resistor could be stable so as to usable in surface mount configurations.